Art of producing designs on leather



Patented Oct. 8, 1940 PATENT OFFICE ART OF PRODUCING DESIGNS N LEATHER Willard Helburn, Cambridge, Mass, assignor to Willard Helburn, 1110., Salem, Mass, at corpora.-

tion of Massachusetts No Drawing. Application January 20, 1939', Serial No. 251,925

2 Claims.

This invention relates to an improvement in the art of producing designs on leather and more particularly to the production of designs by the application of chemicals to leather such as sheepskin, kidskin, goatskin or the like.

I have discovered that designs can be produced upon leather by the application of chemicals to the surface of the leather. Various chemicals may be employed such as concentrated solutions of hygroscopic, highly ionizable agents as, for example, calcium chloride, calcium nitrate, zinc chloride or zinc nitrate. I have found calcium chloride particularly desirable because it is cheap and easy to obtain, and I will describe the invention as embodying the use of that chemical. It will be understood, however, that the invention is not limited to the use of this chemical alone and that other chemicals, producing the same result, may be employed.

I have discovered that when a drop of a concentrated solution of calcium chloride falls upon a piece of leather and is absorbed thereby a chemical reaction takes place with the evolution of heat. The fibres of the leather on which the solution falls are penetrated by the calcium chloride and contract or shrink. Such fibres, however, do not become dry or brittle and the life of the leather is not impaired thereby. As a result of this shrinking of the fibres the leather adjacent thereto is caused to swell or pucker the flesh side presenting a puffed or convex appearance and the grain side a complementary depressed or concave appearance. This action takes place when the drop falls on either side of the leather but is more rapid and more effective when the drop falls on the flesh side where the fibres are more open and porous.

In order to depict upon the leather a complete design or pattern, the concentrated solution is laid in a line as with a glass rod or pen guided 5 by a rule or template. The lining of the design is preferably performed gradually so that the untreated portion is free to swell or pucker relative to one line at a time.

The portion of the leather upon which the solution is applied becomes hard but does not become dry or brittle as would be the case if subjected to a severe heat. The design is permanent- 1y incorporated with the leather and no way has been discovered to eradicate it.

I claim:

1. The process of producing designs upon leather including the step of applying a concentrated chemical hygroscopic solution to certain portions of the leather whereby the fibre of the portions so treated is caused to contract, and the areas adjacent said portions are caused to swell or pucker presenting a puffed or convex appearance on the flesh side, and a depressed or concave appearance on the grain side.

2. The process of producing designs upon leather including the step of applying a concentrated solution of calcium chloride to certain portions of the leather whereby the fibre of the portions so treated is caused to contract, and the areas adjacent said portions are caused to swell or pucker presenting a puiTed or convex appear ance on the flesh side, and a depressed or concave appearance on the grain side.

WILLARD HELBURN. 

